Seconded on Tuta. I'm currently pretty locked into the Proton ecosystem, but I have a Tuta account as well, and it's pretty usable if all you really care about is having an email that works. (haven't used their calendar yet, so I can't speak to it)

Definitely less feature-rich than Proton though. Worse spam filter, more basic UI, no auto-categorization of email by topic, etc.